Trianco TRG80 - fire keeps dying

[Terrywookfit]

Feed & Expansion.
Just wiggle ball valve and check water is above outlet.

 

[Falladaboy]

Tank is about half full, ball valve shut off as it should be, and yes, water level is just above the brass inlet valve assembly at the wall of the tank. Water is clear, but there are some evil-looking reddish scummy deposits in there, on the bottom and around the walls. But it's been like that for years, I think.

 

[oilhead]

The Flue has nothing to do with the air supply for combustion. That is the fans purpose.
It is a FORCED DRAUGHT appliance.
A blocked flue will cause the Fume switch to operate killing the fan supply.

I agree that the fuel is the most likely cause.

Surely, the fan will only supply as much air as can be passed through the flueways, just as on oil boilers. There is a threshold below which combustion can be affected before the fume switch cuts off the power.

 

[Terrywookfit]

The fan is only a Shaded pole motor to supply just enough air for the firebed. The fuel feed is by gravity so if the FLUEWAYS are restricted less fuel is burned.
The secondary air ducts just ensure complete combustion.
The Fume switch is simply a thermostat mounted at the side of the draught divertor which operates if the SECONDARY flue is blocked.

The secondary flue and draught flap create a steady pull to REMOVE POC.

An oil burner will continue to fire at its set rate and soot up (As you know so well)!!

 

[Falladaboy]

I have removed the fire grate and the heavy ram cover, can see the 2 secondary air ducts, but am really struggling to get to them! I'm at full stretch, can just manage to get an old toothbrush in there, but have no purchase on it, as I have to hold it just between two fingers. You need a contortionist to clean those ducts out - or a trained mouse. But I don't think they are clogged, to be honest; I also tried using a 6" coach bolt as a scraper, and when fully inserted it comes up against something hard and metallic. I'm guessing that's the bottom of the flueway block? In which case, both secondary air ducts are clearly open and not blocked. If I could get more purchase on a brush, I might be able to scrub a bit more dust off; but I just can't get the purchase on the toothbrush handle. But I can get the head of the brush 6" up the ducts, where it hits the metal again.
What do you use for the job? An old bottle brush, maybe?
But anyway: does it sound to you as if the airways are sufficiently clear to go ahead and reassemble the ram and grate? I had the chimney swept yesterday - clean bill of health. And I now have some of the new, replacement fuel delivery ready to load. So I'd really appreciate your feedback at this point before proceeding! Many thanks.

 

[Terrywookfit]

The ducts are square at the bottom but turn forwards into a narrow slit.
A small bottle brush is exactly what I use. I scrape the slit with a small screwdriver.

 

[Falladaboy]

Thanks for that - in the meantime, I have been able to see that there is a metal "hood" over the top of the duct opening, which leaves a slit open - looks just like a pillbox in fortifications. The slit is clear - and I can see my toothbrush head moving in behind the slit as it bangs up against the metal hood. So do you think the ducts are clear and ready to go?

 

[Terrywookfit]

YES..... Crack on !!!

 

[Falladaboy]

Pleased to say that the replacement new fuel seems to have solved the main problem: instead of the boiler slowly fading, and then taking hours to recover, with the fan blowing constantly, it now stays hot, and it hasn't gone out, or faded, since I relit it on Thursday evening (so still early days yet!). So a huge thanks to Terrywookfit for guiding me through the process of stripping and cleaning.
That said, I am convinced that the hot water coming out of our taps is NOT as hot as it was previously - i.e. before we started having the problems with the original new fuel a couple of weeks ago. We've got 4 radiators that pick up the heat when the boiler is up to temperature - I class them all as heat leaks, because they get warm/hot without running the central heating; in other words, they are not picking up pumped heat, just the heat that migrates through the pipework from the boiler/hw cylinder. And all four of these radiators are constantly warm to hot at the moment, which tells me that the boiler is maintaining heat (if these rads drop to lukewarm, I know immediately that the boiler is in trouble and the fire is going out).
I already checked the header tank in the loft, and that looks fine - half full of water, ball valve working fine. So I am still baffled by the lower hot water temperature. When the boiler fan stops, I assume the temperature in the water jacket is up to the right level, as set by the thermostat dial on the front of the boiler. The 1" pipes coming off the boiler - and going, I assume, to the hw cylinder - are also hot to the touch: they feel "normal". So how can the water coming OUT of the hw cylinder be cooler than it has always been in the past, before we had these (apparently) fuel-related problems? I simply don't know what else might be causing the issue here.

 

[Falladaboy]

Still having trouble keeping our TRG80 going ... Fired it up with new anthracite grains last Thursday. It went out late Saturday afternoon. It has clung on since then - coming up to four days - but the fire drops right down low, to the point where the heat leak radiators are barely lukewarm (normally very warm to hot), and the fan runs for hours at a time. At this point I am fairly sure the fire is going out, and is beyond recovery. But amazingly it clings on and starts to come up again, eventually reaching temperature and shutting off the fan.
This is not normal. Normally the fan cycles on and off for much shorter periods, and the temperature of the heat leak radiators doesn't vary that much. But now I'm getting these extremes - fire so low that it is on the point of going out, followed by a long, long recovery.
I am also seeing a difference in the contents of the ashcan. Normally I get solid, hard clinkers, where the burnt fuel has fused together. Now I'm getting much softer clumps of powdery ash, with fragile bits of burnt fuel inside: no hard clinkers at all.

My theory is that the solid clinkers act as filters, and let enough draught through to sustain the fire. But this powdery stuff I am now getting probably just blocks the air flow and stifles the fire. So I am thinking my problems are down to poor fuel quality: the stuff just isn't burning right! I'd be glad of anyone's thoughts and past experience!

 

[Terrywookfit]

What settings are the draught flap on the fan throat.

Have you cleaned the blades on the fan properly.

 

[Falladaboy]

The fan blades are looking clean - looking at them from the open side of the casing, without removing the fan from the boiler. I cleaned them thoroughly when I removed the fan a year ago, and I know how the blades get furred up over time. I've cleaned them a good few times over the years. But they are looking clean enough now. And the fire is just coming up again - back from the dead: I would have put money on the fire going out! So I don't really want to remove the fan to check the flap clearances right now - though I will next time the fire does go out.

But the thing is, the settings can't have changed since I started using the new fuel: and I had no problems with combustion before. Unless you are saying that I could live with poor-quality fuel by changing the settings now? I think our consumption is already up, probably because I am running on a higher than usual thermostat setting.

 

[Terrywookfit]

Crap fuel is crap fuel. The lower calorific value means less heat from a given amount.
The increase in ash content proves it is not burning as it should.
You have checked all possible problems with the boiler, so the fuel is the only thing left.
As you say, your problems only started with a new delivery !!

I have seen fuel so bad that I failed to get it burning with a blow torch.!!

 

[Falladaboy]

Thanks for your message. As the boiler went out on me last night anyway, I have removed the fan from its two securing screws - but I can't remove it altogether, as I would prefer, because I don't want to mess with the power supply cable, in case I screw it up. Makes it awkward to work on, of course, because the power cable is so short. Why can't they design it with a plug-in connector?? For the prices Trianco charge, they should do a lot better than this.

I am cleaning the fan vanes - they are not quite as clean as I thought, though it's not enough to impair performance. Awkward to check the flap clearances; the best I could do was find a couple of plywood slips of known thickness, and measure with those. The idle setting is about 4.5 mm, the blast setting is a touch over 9 mm. The gap tapers slightly across the width of the throat, but that's determined by the position of the spindle on which the flap is hung - so that's how it is, how it has always been, and it can't be changed. (And it's never been a problem in the past.)

So I'll get the fan cleaned, refitted, and then light up again, for the third time in a week. I'll e-mail CPL too today, to tell them that their replacement coal was no better than the original order. What will the next load be like, I wonder ...

It would be great to hear back from you today, before I fire up - just in case those flap clearances ring alarm bells for you. But I doubt it somehow.

 

[Terrywookfit]

Those settings should be fine .
Are you sure there is no plug on the fan. ?? I can not remember seeing one without a plug.
If yours is a late model ( Which I rarely come across).......The "Bean counters" may have struck!!
Is the fuel black and shiny? Crap fuel can resemble slate.

Do not expect your fuel supplier to accept that the fuel is crap..........It is my experience that the stock answer will be " No one else has complained".
Unless you have access to A "Bomb Calorimeter" the fuel CV can only be gauged by its performance.
Try making a fire with a small pile outside the boiler.